Miniaturization of the traveling wave ultrasonic linear motor using bimorph transducers

Small-sized ultrasonic linear motors are demanded for replacing pneumatic actuators. We propose a new structure of traveling wave ultrasonic linear motor less than 10 mm in diameter using bimorph transducers. The length of the transducer is determined to be 17 mm being based on finite element analysis for the resonance frequency of 90 kHz. A traveling wave of bending vibration is excited along the transmission bar with the electrical termination at one of the transducers. The maximum speed of 154 mm/s and the maximum thrust of 0.4 N were obtained.